Too many InfluxDB series

[na--]

@danron reported in Slack:

It seems that the implementation of influxdb metrics is not following the recommended practice of not having too many series: https://docs.influxdata.com/influxdb/v1.5/concepts/schema_and_data_layout/#discouraged-schema-design. This since a new series is created for every vu and iteration, so the number of series will be metrics * vus * iterations. It would be better to change the tags vu and iter into fields for influxdb.

From the InfluxDB docs:

Tags containing highly variable information like UUIDs, hashes, and random strings will lead to a large number of series in the database, known colloquially as high series cardinality. High series cardinality is a primary driver of high memory usage for many database workloads.

Even though the iter and vu tags are not sent by default from v0.2.0, they could be manually enabled. We need an option that allows InfluxDB users to specify which of the tags they want to actually be sent as tags and which should be sent as fields. The default value should probably be vu,iter,url (name should probably remain as a tag, because it can be used for aggregation).

[na--]

This was closed by #585